题目
You are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane.
解题思路
取前两点，求斜率，然后用后面的每个点和第一个点求斜率，如果所有的斜率都相同，则所有点共线，并不需要把斜率求出来，只需要记录y轴和x轴的差，相乘就可以了
代码
class Solution:
def checkStraightLine(self, coordinates: List[List[int]]) -> bool:
dy = coordinates[1][1] - coordinates[0][1]
dx = coordinates[1][0] - coordinates[0][0]
for i in range(2, len(coordinates)):
dyp = coordinates[i][1] - coordinates[0][1]
dxp = coordinates[i][0] - coordinates[0][0]
if dy * dxp != dx * dyp:
return False
return True
